SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8359718bf509067cca67faa04e276d0d81f414b35650e8e6ea70f1e5abfd7fd9' 
  AND token = 'QRJEpEvWJc/09cjbo8Wwi+Epw9ECIh1XSUctNZa3zgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables